Experimental observation of liquid–solid transition of nanoconfined water at ambient temperature

Nature Materials (2026)Cite this article Nanoconfined water exhibits many abnormal properties compared with bulk water. However, the origin of those anomalies remains controversial due to the lack of experimental access to the molecular-level details of the hydrogen-bonding network of water within a nanocavity. Here we address this issue by combining scanning probe microscopy with nitrogen-vacancy-centre-based quantum sensing. Such a technique allows us to characterize both dynamics and structure of water confined between a hexagonal boron nitride flake and a hydrophilic diamond surface by nanoscale nuclear magnetic resonance. We observe a liquid–solid phase transition of nanoconfined water at ambient temperature with an onset confinement size of ~1.6 nm, below which the water diffusion is considerably suppressed and the hydrogen-bonding network of water becomes structurally ordered. The complete crystallization is observed below a confinement size of ~1 nm. The liquid–solid transition is further confirmed by molecular dynamics simulation. These findings shed new light on the phase transition of nanoconfined water and may form a unified picture for understanding water anomalies at the nanoscale.This is a preview of subscription content, access via your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $32.99 / 30 days cancel any timeSubscribe to this journal Receive 12 print issues and online access $259.00 per yearonly $21.58 per issueBuy this articleUSD 39.95Prices may be subject to local taxes which are calculated during checkoutThe relevant data supporting the findings of this study are available via Zenodo (https://doi.org/10.5281/zenodo.17555910)82. All other data needed to evaluate the conclusions in the paper are present in the Article or Supplementary Information. Source data are provided with this paper.The code used in this study for the NMR simulations is available via Zenodo (https://doi.org/10.5281/zenodo.17555910)82.Liou, Y. C., Tocilj, A., Davies, P. L. & Jia, Z. C. Mimicry of ice structure by surface hydroxyls and water of a β-helix antifreeze protein. Nature 406, 322–324 (2000).Article CAS PubMed Google Scholar Sui, H. X., Han, B. G., Lee, J. K., Walian, P. & Jap, B. K. Structural basis of water-specific transport through the AQP1 water channel. Nature 414, 872–878 (2001).Article CAS PubMed Google Scholar Joshi, R. K. et al. Precise and ultrafast molecular sieving through graphene oxide membranes. Science 343, 752–754 (2014).Article CAS PubMed Google Scholar Surwade, S. P. et al. Water desalination using nanoporous single-layer graphene. Nat. Nanotechnol. 10, 459–464 (2015).Article CAS PubMed Google Scholar Hanikel, N., Prévot, M. S. & Yaghi, O. M. MOF water harvesters. Nat. Nanotechnol. 15, 348–355 (2020).Article CAS PubMed Google Scholar Logan, B. E. & Elimelech, M. Membrane-based processes for sustainable power generation using water. Nature 488, 313–319 (2012).Article CAS PubMed Google Scholar Holt, J. K. et al. Fast mass transport through sub-2-nanometer carbon nanotubes. Science 312, 1034–1037 (2006).Article CAS PubMed Google Scholar Radha, B. et al. Molecular transport through capillaries made with atomic-scale precision. Nature 538, 222–225 (2016).Article CAS PubMed Google Scholar Fumagalli, L. et al. Anomalously low dielectric constant of confined water. Science 360, 1339–1342 (2018).Article CAS PubMed Google Scholar Chin, H. T. et al. Ferroelectric 2D ice under graphene confinement. Nat. Commun. 12, 6291 (2021).Article CAS PubMed PubMed Central Google Scholar Khan, S. H., Matei, G., Patil, S. & Hoffmann, P. M. Dynamic solidification in nanoconfined water films. Phys. Rev. Lett. 105, 106101 (2010).Article PubMed Google Scholar Zangi, R. & Mark, A. E. Monolayer ice. Phys. Rev. Lett. 91, 025502 (2003).Article PubMed Google Scholar Giovambattista, N., Rossky, P. J. & Debenedetti, P. G. Phase transitions induced by nanoconfinement in liquid water. Phys. Rev. Lett. 102, 050603 (2009).Article PubMed Google Scholar Falk, K., Sedlmeier, F., Joly, L., Netz, R. R. & Bocquet, L. Molecular origin of fast water transport in carbon nanotube membranes: superlubricity versus curvature dependent friction. Nano Lett. 10, 4067–4073 (2010).Article CAS PubMed Google Scholar Han, S. H., Choi, M. Y., Kumar, P. & Stanley, H. E. Phase transitions in confined water nanofilms. Nat. Phys. 6, 685–689 (2010).Article CAS Google Scholar Kastelowitz, N. & Molinero, V. Ice-liquid oscillations in nanoconfined water. ACS Nano 12, 8234–8239 (2018).Article CAS PubMed Google Scholar Kapil, V. et al. The first-principles phase diagram of monolayer nanoconfined water. Nature 609, 512–516 (2022).Article CAS PubMed Google Scholar Jiang, J. et al. Rich proton dynamics and phase behaviours of nanoconfined ices. Nat. Phys. 20, 456–464 (2024).Article CAS Google Scholar Ma, R. Z. et al. Atomic imaging of the edge structure and growth of a two-dimensional hexagonal ice. Nature 577, 60–63 (2020).Article CAS PubMed Google Scholar Hong, J. N. et al. Imaging surface structure and premelting of ice Ih with atomic resolution. Nature 630, 375–380 (2024).Article CAS PubMed Google Scholar Algara-Siller, G. et al. Square ice in graphene nanocapillaries. Nature 519, 443–445 (2015).Article CAS PubMed Google Scholar Grünberg, B. et al. Hydrogen bonding of water confined in mesoporous silica MCM-41 and SBA-15 studied by H solid-state NMR. Chemistry 10, 5689–5696 (2004).Article PubMed Google Scholar Ishizaki, T., Maruyama, M., Furukawa, Y. & Dash, J. G. Premelting of ice in porous silica glass. J. Cryst. Growth 163, 455–460 (1996).Article CAS Google Scholar Sovago, M. et al. Vibrational response of hydrogen-bonded interfacial water is dominated by intramolecular coupling. Phys. Rev. Lett. 100, 173901 (2008).Article PubMed Google Scholar Wang, Y. H. et al. In situ Raman spectroscopy reveals the structure and dissociation of interfacial water. Nature 600, 81–85 (2021).Article CAS PubMed Google Scholar Xu, Y., Ma, Y. B., Gu, F., Yang, S. S. & Tian, C. S. Structure evolution at the gate-tunable suspended graphene-water interface. Nature 621, 506–510 (2023).Article CAS PubMed Google Scholar Alabarse, F. G. et al. Freezing of water confined at the nanoscale. Phys. Rev. Lett. 109, 035701 (2012).Article CAS PubMed Google Scholar Staudacher, T. et al. Nuclear magnetic resonance spectroscopy on a (5-nanometer)3 sample volume. Science 339, 561–563 (2013).Article CAS PubMed Google Scholar Schmitt, S. et al. Submillihertz magnetic spectroscopy performed with a nanoscale quantum sensor. Science 356, 832–837 (2017).Article CAS PubMed Google Scholar Degen, C. L., Reinhard, F. & Cappellaro, P. Quantum sensing. Rev. Mod. Phys. 89, 035002 (2017).Article Google Scholar Du, J. F., Shi, F. Z., Kong, X., Jelezko, F. & Wrachtrup, J. Single-molecule scale magnetic resonance spectroscopy using quantum diamond sensors. Rev. Mod. Phys. 96, 025001 (2024).Article CAS Google Scholar Zheng, W. T. et al. Coherence enhancement of solid-state qubits by local manipulation of the electron spin bath. Nat. Phys. 18, 1317–1323 (2022).Article CAS Google Scholar DeVience, S. J. et al. Nanoscale NMR spectroscopy and imaging of multiple nuclear species. Nat. Nanotechnol. 10, 129–136 (2015).Article CAS PubMed Google Scholar Aslam, N. et al. Nanoscale nuclear magnetic resonance with chemical resolution. Science 357, 67–71 (2017).Article CAS PubMed Google Scholar Bian, K. et al. Nanoscale electric-field imaging based on a quantum sensor and its charge-state control under ambient condition. Nat. Commun. 12, 2457 (2021).Article CAS PubMed PubMed Central Google Scholar Bian, K. et al. A scanning probe microscope compatible with quantum sensing at ambient conditions. Rev. Sci. Instrum. 95, 053707 (2024).Article CAS PubMed Google Scholar Zhu, Y. B., Wang, F. C., Bai, J. I., Zeng, X. C. & Wu, H. A. Compression limit of two-dimensional water constrained in graphene nanocapillaries. ACS Nano 9, 12197–12204 (2015).Article CAS PubMed Google Scholar Leng, Y. S. & Cummings, P. T. Hydration structure of water confined between mica surfaces. J. Chem. Phys. 124, 074711 (2006).Article Google Scholar Lane, J. M. D., Chandross, M., Stevens, M. J. & Grest, G. S. Water in nanoconfinement between hydrophilic self-assembled monolayers. Langmuir 24, 5209–5212 (2008).Article CAS PubMed Google Scholar Kumar, H., Dasgupta, C. & Maiti, P. K. Phase transition in monolayer water confined in Janus nanopore. Langmuir 34, 12199–12205 (2018).Article CAS PubMed Google Scholar Staudacher, T. et al. Probing molecular dynamics at the nanoscale via an individual paramagnetic centre. Nat. Commun. 6, 8527 (2015).Article CAS PubMed Google Scholar Yang, Z. P. et al. Detection of magnetic dipolar coupling of water molecules at the nanoscale using quantum magnetometry. Phys. Rev. B 97, 205438 (2018).Article CAS Google Scholar Baldwin, C. G., Downes, J. E., McMahon, C. J., Bradac, C. & Mildren, R. P. Nanostructuring and oxidation of diamond by two-photon ultraviolet surface excitation: an XPS and NEXAFS study. Phys. Rev. B 89, 195422 (2014).Article Google Scholar Sangtawesin, S. et al. Origins of diamond surface noise probed by correlating single-spin measurements with surface spectroscopy. Phys. Rev. X. 9, 031052 (2019).CAS Google Scholar Laage, D., Elsaesser, T. & Hynes, J. T. Water dynamics in the hydration shells of biomolecules. Chem. Rev. 117, 10694–10725 (2017).Article CAS PubMed PubMed Central Google Scholar Xu, K., Cao, P. G. & Heath, J. R. Graphene visualizes the first water adlayers on mica at ambient conditions. Science 329, 1188–1191 (2010).Article CAS PubMed Google Scholar Shin, D., Hwang, J. & Jhe, W. Ice-VII-like molecular structure of ambient water nanomeniscus. Nat. Commun. 10, 286 (2019).Article PubMed PubMed Central Google Scholar Martelli, F., Calero, C. & Franzese, G. Redefining the concept of hydration water near soft interfaces. Biointerphases 16, 020801 (2021).Article CAS PubMed Google Scholar Wu, D. et al. Probing structural superlubricity of two-dimensional water transport with atomic resolution. Science 384, 1254–1259 (2024).Article CAS PubMed Google Scholar Maletinsky, P. et al. A robust scanning diamond sensor for nanoscale imaging with single nitrogen-vacancy centres. Nat. Nanotechnol. 7, 320–324 (2012).Article CAS PubMed Google Scholar Boss, J. M., Cujia, K. S., Zopes, J. & Degen, C. L. Quantum sensing with arbitrary frequency resolution. Science 356, 837–840 (2017).Article CAS PubMed Google Scholar Schwartz, I. et al. Robust optical polarization of nuclear spin baths using Hamiltonian engineering of nitrogen-vacancy center quantum dynamics. Sci. Adv. 4, eaat8978 (2018).Article CAS PubMed PubMed Central Google Scholar Zhao, N. et al. Sensing single remote nuclear spins. Nat. Nanotechnol. 7, 657–662 (2012).Article CAS PubMed Google Scholar Bocquet, L. Nanofluidics coming of age. Nat. Mater. 19, 254–256 (2020).Article CAS PubMed Google Scholar Casola, F., van der Sar, T. & Yacoby, A. Probing condensed matter physics with magnetometry based on nitrogen-vacancy centres in diamond. Nat. Rev. Mater. 3, 17088 (2018).Article CAS Google Scholar Giessibl, F. J. The qPlus sensor, a powerful core for the atomic force microscope. Rev. Sci. Instrum. 90, 011101 (2019).Article PubMed Google Scholar de Oliveira, F. F. et al. Tailoring spin defects in diamond by lattice charging. Nat. Commun. 8, 15409 (2017).Article Google Scholar Rugar, D. et al. Proton magnetic resonance imaging using a nitrogen-vacancy spin sensor. Nat. Nanotechnol. 10, 120–124 (2015).Article CAS PubMed Google Scholar Lovchinsky, I. et al. Magnetic resonance spectroscopy of an atomically thin material using a single-spin qubit. Science 355, 503–507 (2017).Article CAS PubMed Google Scholar Wastl, D. S., Weymouth, A. J. & Giessibl, F. J. Optimizing atomic resolution of force microscopy in ambient conditions. Phys. Rev. B 87, 245415 (2013).Article Google Scholar Glenn, D. R. et al. High-resolution magnetic resonance spectroscopy using a solid-state spin sensor. Nature 555, 351–354 (2018).Article CAS PubMed Google Scholar Shannon, C. E. Communication in the presence of noise. Proc. Inst. Radio Eng. 37, 10–21 (1949).

Google Scholar Lu, S. H. et al. Ground-state structure of oxidized diamond (100) surface: an electronically nearly surface-free reconstruction. Carbon 159, 9–15 (2020).Article CAS Google Scholar Zamborlini, G. et al. Nanobubbles at GPa pressure under graphene. Nano Lett. 15, 6162–6169 (2015).Article CAS PubMed Google Scholar Khestanova, E., Guinea, F., Fumagalli, L., Geim, A. K. & Grigorieva, I. V. Universal shape and pressure inside bubbles appearing in van der Waals heterostructures. Nat. Commun. 7, 12587 (2016).Article CAS PubMed PubMed Central Google Scholar Vasu, K. S. et al. Van der Waals pressure and its effect on trapped interlayer molecules. Nat. Commun. 7, 12168 (2016).Article CAS PubMed PubMed Central Google Scholar Lin, S. T., Blanco, M. & Goddard III, W. The two-phase model for calculating thermodynamic properties of liquids from molecular dynamics: validation for the phase diagram of Lennard-Jones fluids. J. Chem. Phys. 119, 11792–11805 (2003).Article CAS Google Scholar Jorgensen, W. L., Maxwell, D. S. & TiradoRives, J. Development and testing of the OPLS all-atom force field on conformational energetics and properties of organic liquids. J. Am. Chem. Soc. 118, 11225–11236 (1996).Article CAS Google Scholar Abascal, J. L. F., Sanz, E., Fernández, R. G. & Vega, C. A potential model for the study of ices and amorphous water: TIP4P/Ice. J. Chem. Phys. 122, 234511 (2005).Article CAS PubMed Google Scholar Conde, M. M., Rovere, M. & Gallo, P. High precision determination of the melting points of water TIP4P/2005 and water TIP4P/Ice models by the direct coexistence technique. J. Chem. Phys. 147, 244506 (2017).Article CAS PubMed Google Scholar Johnston, J. C., Kastelowitz, N. & Molinero, V. Liquid to quasicrystal transition in bilayer water. J. Chem. Phys. 133, 154516 (2010).Article PubMed Google Scholar Babin, V., Leforestier, C. & Paesani, F. Development of a ‘first principles’ water potential with flexible monomers: dimer potential energy surface, VRT spectrum, and second virial coefficient. J. Chem. Theory Comput. 9, 5395–5403 (2013).Article CAS PubMed Google Scholar Babin, V., Medders, G. R. & Paesani, F. Development of a ‘first principles’ water potential with flexible monomers. II: trimer potential energy surface, third virial coefficient, and small clusters. J. Chem. Theory Comput. 10, 1599–1607 (2014).Article CAS PubMed Google Scholar Medders, G. R., Babin, V. & Paesani, F. Development of a ‘first principles’ water potential with flexible monomers. III. Liquid phase properties. J. Chem. Theory Comput. 10, 2906–2910 (2014).Article CAS PubMed Google Scholar Thompson, A. P. et al. LAMMPS—a flexible simulation tool for particle-based materials modeling at the atomic, meso, and continuum scales. Comput. Phys. Commun. 271, 108171 (2022).Article CAS Google Scholar Lee, K., Murray, ÉD., Kong, L. Z., Lundqvist, B. I. & Langreth, D. C. Higher-accuracy van der Waals density functional. Phys. Rev. B 82, 081101(R) (2010).Article Google Scholar Brandenburg, J. G., Zen, A., Alfè, D. & Michaelides, A. Interaction between water and carbon nanostructures: how good are current density functional approximations?. J. Chem. Phys. 151, 164702 (2019).Article PubMed Google Scholar Goedecker, S., Teter, M. & Hutter, J. Separable dual-space Gaussian pseudopotentials. Phys. Rev. B 54, 1703–1710 (1996).Article CAS Google Scholar Kühne, T. D. et al. CP2K: an electronic structure and molecular dynamics software package—quickstep: efficient and accurate electronic structure calculations. J. Chem. Phys. 152, 194103 (2020).Article PubMed Google Scholar Calero, C. & Franzese, G. Water under extreme confinement in graphene: oscillatory dynamics, structure, and hydration pressure explained as a function of the confinement width. J. Mol. Liq. 317, 114027 (2020).Article CAS Google Scholar Leoni, F., Calero, C. & Franzese, G. Nanoconfined fluids: uniqueness of water compared to other liquids. ACS Nano 15, 19864–19876 (2021).Article CAS PubMed PubMed Central Google Scholar Zheng, W. et al. Experimental observation of liquid-solid transition of nanoconfined water at ambient temperature. Zenodo https://doi.org/10.5281/zenodo.17555910 (2025).Download referencesWe thank L. Yang and C. Yu from Peking University (PKU) for their help with the 2D material transfer and fabrications, and N. Zhao from Beijing Computational Science Research Center (CSRC) for meaningful guidance and discussions on the NMR simulations. This work was supported by the National Key R&D Program under grant number 2021YFA1400500; the Program under grant number 2023ZD0301300; the National Natural Science Foundation of China under grant numbers 11888101, 21725302, 12474160, U22A20260 and 12250001; the Strategic Priority Research Program of the Chinese Academy of Sciences under grant number XDB28000000; and the Beijing Municipal Science & Technology Commission under grant number Z231100006623009. W.Z. acknowledges the China Postdoctoral Science Foundation under grant number 2022M710235. Y.J. acknowledges the New Cornerstone Science Foundation through the New Cornerstone Investigator Program and the XPLORER PRIZE, and the Beijing Outstanding Young Scientist Program under grant number JWZQ20240101002. X.C.Z. acknowledges support from the Hong Kong Global STEM Professorship Scheme and the Research Grants Council of Hong Kong (GRF grant numbers 11204123 and 11302225). J.J. acknowledges funding support from the National Natural Science Foundation of China (grant number 22303072). R.S., A.D. and J.W. acknowledge the BMBF via Clusters4Future: QSens and the DFG under grant numbers FOR 2724, GRK 2642 and WR 28/34-1.These authors contributed equally: Wentian Zheng, Shichen Zhang, Jian Jiang.International Center for Quantum Materials, School of Physics, Peking University, Beijing, People’s Republic of ChinaWentian Zheng, Shichen Zhang, Yipeng He, Ke Bian, En-Ge Wang & Ying JiangDepartment of Material Science and Engineering, City University of Hong Kong, Hong Kong, People’s Republic of ChinaJian Jiang & Xiao Cheng ZengShenzhen Research Institute, City University of Hong Kong, Shenzhen, People’s Republic of ChinaJian Jiang3rd Institute of Physics, University of Stuttgart and Institute for Quantum Science and Technology (IQST), Stuttgart, GermanyRainer Stöhr, Andrej Denisenko & Jörg WrachtrupMax Planck Institute for Solid State Research, Stuttgart, GermanyRainer Stöhr, Andrej Denisenko & Jörg WrachtrupHong Kong Institute for Clean Energy, City University of Hong Kong, Hong Kong, People’s Republic of ChinaXiao Cheng ZengInterdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing, People’s Republic of ChinaKe Bian, En-Ge Wang & Ying JiangCollaborative Innovation Center of Quantum Matter, Beijing, People’s Republic of ChinaEn-Ge Wang & Ying JiangTsientang Institute for Advanced Study, Zhejiang, People’s Republic of ChinaEn-Ge WangNew Cornerstone Science Laboratory, Peking University, Beijing, People’s Republic of ChinaYing JiangSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarY.J., K.B. and E.-G.W. supervised the project. K.B. and Y.J. designed the experiment. R.S. and A.D. grew the diamond chips and fabricated the shallow NVs. S.Z. and W.Z. transferred the hBN flakes and fabricated the hBN–diamond structure. W.Z. and S.Z. performed the experiments and data acquisition. W.Z., S.Z., J.J., K.B., Y.H., J.W., X.C.Z., Y.J. and E.-G.W. performed the experimental data analysis and interpretation. J.J. and X.C.Z. performed the MD simulations. W.Z., S.Z., J.J. and K.B. performed the NMR simulations. W.Z., K.B., S.Z., J.J., X.C.Z., Y.J. and E.-G.W. wrote the manuscript with input from all other authors. All authors commented on the final manuscript.Correspondence to Xiao Cheng Zeng, Ke Bian, En-Ge Wang or Ying Jiang.The authors declare no competing interests.Nature Materials thanks Giancarlo Franzese, Francesco Paesani and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.(a) Topographic image of diamond surface without the hBN flake, corresponding to the open system. The position of the NV center was determined by the procedures described in Supplementary Fig. 1, denoted as an orange dashed circle with the nearby reference protrusion being marked by an arrow. (b) Topographic image of the same area with the hBN flake and without confined water molecules, which was confirmed by the nanoscale-NMR measurement. (c) Z-profile was measured along the dashed line in (a) (black) and in (b) (red). The position of the NV center was estimated with an uncertainty denoted by the shades. The measured height difference of the two profiles indicates the thickness of the intrinsic water layer on the diamond surface: dwater = 2.7 ± 0.2 nm. Scale bar: 250 nm.Source data(a) Left panel: correlation spectroscopy at a confinement size of 0.7 ± 0.3 nm measured by an NV with depth of 4.39 ± 0.49 nm. By using a sum of cosine functions with multiple frequencies and an exponentially decayed envelope \(S\left(\widetilde{\tau }\right)={e}^{-\widetilde{\tau }/{T}_{{\rm{corr}}}}{\sum }_{i}{S}_{i}\cos \left({2\pi f}_{i}\widetilde{{\rm{\tau }}}+{\varphi }_{i}\right)\), the signal was fitted with a time constant of Tcorr = 183.7 ± 29.5 µs. Right panel: the corresponding power spectrum showing a multi-peak feature. (b) Left panel: correlation spectroscopy at a confinement size of 1.5 ± 0.4 nm measured by an NV with depth of 5.13 ± 0.65 nm. The signal was fitted with a time constant of Tcorr = 224.3 ± 45.1 µs. Right panel: the corresponding power spectrum showing two peaks.Source data(a) The hydroxylated (100) surface with carbonyl(-C = O), ether(C-O-C), and hydroxyl(-OH) functional groups, and (b) the methoxy-acetone oxidized diamond (100) surface with carbonyl(-C = O) and ether(C-O-C) functional groups adopted for classical MD simulation. Red, white, and gray balls represent oxygen, hydrogen, and carbon atoms, respectively. (c) The calculated diffusion coefficients of the whole water layer in three different confinement systems from MD simulation: (1) Water confined between a hydroxylated hydrophilic diamond surface and a hydrophobic hBN surface (gray), (2) water confined between a methoxy-acetone oxidized hydrophilic diamond surface and a hydrophobic hBN surface (red), and (3) water confined between two hydrophobic hBN surfaces (blue). Dt are presented as mean values ± standard deviations, derived from 3 simulations.Source dataRotational coefficients (Dr) were calculated through the statistical trajectories of water molecules, for dconfine ranging from 1 nm to 6 nm, where they exhibited a large suppression at dconfine < 2 nm. Dr are presented as mean values ± standard deviations, derived from 3 simulations.Source dataCalculated local q6 Steinhardt parameters of the confined water layer with dconfine ranging from 0.6 nm to 6 nm by using the TIP4P/Ice model. q6 bond-order parameter quantifies the six-fold symmetry of the hydrogen bond structures. The results show increased ordering with decreasing confinement size, with two transition points of slope change (marked by arrows) at approximately 2.1 nm and 1.2 nm, respectively. The increase in q6 at ~2.1 nm indicates the onset of the liquid-solid transition, while the sharp increase in q6 at ~1.2 nm indicates the rapid crystallization.Source dataSupplementary Texts 1–8, Table 1, Figs. 1–11 and refs. 1–21.Raw data for Supplementary Fig. 1.Raw data for Supplementary Fig. 2c,d.Raw data for Supplementary Fig. 3b.Raw data for Supplementary Fig. 4b.Raw data for Supplementary Fig. 5.Raw data for Supplementary Fig. 8.Raw data for Supplementary Fig. 10d,e.Raw data for Supplementary Fig. 11.Raw data for Figs. 1d–g.Raw data for Fig. 2a–c.Raw data for Fig. 3a,b.Raw data and code for Fig. 4d.Raw data for Extended Data Fig. 1a–c.Raw data for Extended Data Fig. 2.Raw data for Extended Data Fig. 3.Raw data for Extended Data Fig. 4.Raw data for Extended Data Fig. 5.Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Reprints and permissionsZheng, W., Zhang, S., Jiang, J. et al. Experimental observation of liquid–solid transition of nanoconfined water at ambient temperature. Nat. Mater. (2026). https://doi.org/10.1038/s41563-025-02456-8Download citationReceived: 06 March 2025Accepted: 24 November 2025Published: 12 January 2026Version of record: 12 January 2026DOI: https://doi.org/10.1038/s41563-025-02456-8Anyone you share the following link with will be able to read this content:Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative